The Core facility of this center includes: 1) a laboratory for protein chemistry designed to facilitate studies on membrane proteins (as described in terms of its current activities on a separate form) and, 2) a scanning electron microscope laboratory for the study of the fine structure of cells and subcellular components. The laboratory has a high resolution SEM (JEOL SFMS-30) and a TEM with a scanning attachment (JEM 100 CX). The group in the scanning electron microscope laboratory works on developing specimen preparation techniques (fixation, support of fine structures during dehydration, metal coating) that will allow the visualization of surface detail down to approximately 3 nm. Biological specimens under investigation are: glomerular basement membranes (K. Peters, M.G. Farquhar and G.E. Palade), retinal discs (obtaind from outer rod segments (K.R. Peters and D. Papermaster)), and intestinal brush borders (K.R. Peters, P. Male and G.E. Palade).